The present invention relates generally to a fuel storage and dispensing system and, more particularly, to a system which employs a storage tank, a fuel dispenser, a fuel dispensing nozzle and spout, a boot, a pressure relief chamber, a filter system, and a pump to reduce the discharge of pollutants from underground fuel storage tanks, as well as the emission of hydrocarbon vapors above ground during fueling. The system is arranged to discharge pollutant free air through an air exhaust port when the pressure within the system reaches a predetermined level. Air to be discharged is separated from fuel vapor within the filter system prior to its discharge.
In addition to the capture of pollutants that are vented from underground fuel storage tanks, the petroleum industry has increasingly made provisions for recovering fuel vapors that are displaced from a vehicle fuel tank as fuel is discharged therein. Generally, there are two types of systems designed for vapor recoveryxe2x80x94pressure balance recovery systems and vacuum-induced vapor recovery systems.
Pressure balance systems involve the addition of a vapor return conduit system that extends from a dispenser nozzle, through a hose, to a dispenser pedestal and then through an underground conduit system to a point of disposal. Most frequently, the means of disposal is simply to return the vapors to the storage tank from which fuel is drawn to fill the fuel tank of the vehicle. As fuel is withdrawn from the storage tank in fueling a vehicle, the vapor space within the storage tank is increased. Conversely, as fuel is introduced into the fuel tank of a vehicle, vapor space is decreased to essentially an identical extent. The resultant pressure differentials cause the vapors to flow through the vapor conduit system from the nozzle back into the storage tank, thereby creating a pressure balance.
Vacuum-induced vapor recovery systems employ vapor recovery lines as well as a vacuum assist to enhance the return of displaced vapors to the storage tanks. Vacuum assist nozzles also include a vapor return passage for connection with a coaxial hose, at the opposite or hose attachment end of the nozzle. However, the nozzles employed in vacuum assist systems are not without faults. The coaxial design of the nozzle is prone to dripping once fueling is complete and the nozzle is discharged from the vehicle tank inlet pipe. Such dripping can lead to significant emission of volatile organic compounds (xe2x80x9cVOCxe2x80x9d) into the environment.
Accordingly, the present inventors have recognized a need for improvements in fuel, storage and dispensing system design, which is effective in reducing fugitive emissions, as well as improvements in the design of nozzles, boots, and other associated assemblies for vacuum-induced vapor recovery systems.
The present invention meets the above-mentioned needs by providing a fuel storage and dispensing system, a fuel dispensing nozzle and spout assembly, a pressure relief assembly, a vapor recovery boot, and a Venturi shut-off assembly for a fuel dispensing nozzle and spout. Although the present invention is not limited to specific advantages or functionality, it is noted that each embodiment of the instant invention is effective in reducing the emission of volatile organic compounds into the environment both during fueling, as well as during storage of gasoline.
In accordance with one embodiment of the present invention, a fuel storage and dispensing system is provided comprising at least one storage tank, an air exhaust port, at least one fuel dispenser, a fuel dispensing nozzle, a rigid, fuel dispensing spout, a boot, a pressure relief chamber, a filter system, and at least one pump. The storage tank includes at least one fluid vent port and at least one pollutant return port. At least one fuel delivery port and at least one vapor return port are configured to couple the storage tank to the fuel dispenser.
The fuel dispenser comprises a vapor assist hose, a meter, and a dispenser coupling. The vapor assist hose defines a fuel dispensing passage and a vapor recovery passage, wherein the vapor assist hose extends from a fuel input end to a fuel dispensing end. The meter is configured to provide an indication of an amount of fuel dispensed through the vapor assist hose. The dispenser coupling is configured to place the fuel dispensing passage in communication with the fuel delivery port and the vapor recovery passage in communication with the vapor return port.
The fuel dispensing nozzle defines a hose attachment end and a spout attachment end. The hose attachment end is coupled with the fuel dispensing end of the vapor assist hose. The spout attachment end further defines a vapor return opening, and the vapor recovery passage of the vapor assist hose is in communication with the vapor return opening. The vapor return opening defined by the spout attachment end of the fuel dispensing nozzle can be positioned about an outer periphery of the rigid, fuel dispensing spout.
The rigid, fuel dispensing spout is coupled to the spout attachment end of the fuel dispensing nozzle. The fuel dispensing passage of the vapor assist hose is in communication with the rigid, fuel dispensing spout. The rigid, fuel dispensing spout further defines a non-coaxial fuel tube. The non-coaxial fuel tube can be configured to be substantially dripless.
The rigid, fuel dispensing spout can further comprise mounting hardware having an outer boundary. The mounting hardware can be configured to attach the rigid, fuel dispensing spout to the spout attachment end of the fuel dispensing nozzle. The vapor return opening can be positioned outside of the outer boundary of the mounting hardware on the spout attachment end of the fuel dispensing nozzle.
The boot defines a proximal end and a distal end. The proximal end is coupled to the spout attachment end of the fuel dispensing nozzle. The distal end is configured for communication with a surface proximate a fuel tank inlet pipe of a vehicle during fueling. The boot is positioned surrounding the rigid, fuel dispensing spout and defines an annular passage configured for receiving fuel vapor displaced from the fuel tank inlet pipe of the vehicle during fueling. The annular passage is in communication with the vapor return opening in the spout attachment end of the fuel dispensing nozzle.
The pressure relief chamber is in communication with the fuel dispensing passage of the vapor assist hose. The pressure relief chamber comprises a bleed hole and a fluid volume sufficient to enable fuel traveling within the fuel dispensing passage of the vapor assist hose to create a pressure relief vacuum within the chamber. The pressure relief vacuum has a magnitude sufficient to compensate for high temperature pressure build-up in the vapor assist hose.
The filter system comprises a filter input port coupled to the fluid vent port. The at least one pump is configured to cause fluid to pass through the filter input port. The storage tank, the filter system, and the pump are configured such that the storage tank and additional portions of the fuel storage and dispensing system operate below atmospheric pressure.
The fuel storage and dispensing system can further comprise at least one pressure sensor. The pressure sensor is configured to monitor pressure at one or more diagnostic points within the fuel storage and dispensing system. The pressure sensor can be configured to provide an indication of pressure. The indication of pressure can be greater than, less than, or equal to atmospheric pressure. The pressure sensor can be configured to provide an indication of pressure within or at one or more of the storage tank, the fluid vent port, the pollutant return port, the air exhaust port, the fuel dispenser, the vapor return port, the vapor assist hose, the vapor recovery passage, the dispenser coupling, the fuel dispensing nozzle, the pressure relief chamber, the vapor return opening, the boot, the filter system, and the pump. The pressure sensor can be coupled to a dispenser display. The dispenser display is configured to provide an indication of pressure.
The fuel storage and dispensing system can further comprise a data processor that is coupled to the pressure sensor. The data processor is configured to process pressure measurements received from the pressure sensor, and to generate a pressure data profile of the fuel storage and dispensing system. The data processor can be further configured to generate a leak alarm when pressure monitored at one of the one or more diagnostic points exceeds a predetermined level. The data processor can be further configured to correlate a position of a selected diagnostic point with the pressure monitored exceeding a predetermined level. Moreover, the data processor can be further configured to generate a vapor return port blockage signal when pressure monitored at the vapor return port exceeds a predetermined level. The system can further comprise a wireless transmitter in communication with the pressure sensor. The wireless transmitter is configured to transmit a signal indicative of pressure.
The fuel storage and dispensing system of the present embodiment can further comprise a microwave unit arranged to direct microwave radiation at fluid released through the air exhaust port.
In accordance with another embodiment of the present invention, a fuel dispensing nozzle and spout assembly is provided comprising a fuel dispensing nozzle and a rigid, fuel dispensing spout. The fuel dispensing nozzle defines a hose attachment end and a spout attachment end. The hose attachment end is coupled with a fuel dispensing end of a vapor assist hose. The spout attachment end further defines a vapor return opening. The vapor return opening defined by the spout attachment end of the fuel dispensing nozzle can be positioned about an outer periphery of the rigid, fuel dispensing spout. A vapor recovery passage of the vapor assist hose is in communication with the vapor return opening. The rigid, fuel dispensing spout is coupled to the spout attachment end of the fuel dispensing nozzle. A fuel dispensing passage of the vapor assist hose is in communication with the rigid, fuel dispensing spout, which further defines a non-coaxial fuel tube. The non-coaxial fuel tube can be configured to be substantially dripless. The spout can be configured to fit within a fuel tank inlet pipe of a vehicle for fueling of the vehicle.
The rigid, fuel dispensing spout can further comprise mounting hardware having an outer boundary. The mounting hardware can be configured to attach the rigid, fuel dispensing spout to the spout attachment end of the fuel dispensing nozzle. The vapor return opening can be positioned outside of the outer boundary of the mounting hardware on the spout attachment end of the fuel dispensing nozzle.
The rigid, fuel dispensing spout can further define a mid section and the spout can be partially vertically bent down at the mid section to define a bend. The bend can be about 22xc2x0 down vertically. The spout can further define a sidewall, a shutoff sensing tube positioned within the spout, and an inlet hole. The inlet hole completely traverses the sidewall of the rigid spout and the shutoff sensing tube is in communication with the inlet hole. The shutoff sensing tube can include a check valve and is coupled to a Venturi shut-off valve positioned within the fuel dispensing nozzle.
The shutoff sensing tube can further define a trap. The trap is oriented forward the inlet hole and can comprise a greater than 90xc2x0 bend that defines a collection area. The shutoff sensing tube can define an inside diameter that comprises a TEFLON(copyright) or polytetrafluoroethylene coating. In addition, the spout can further define a spout gutter that is defined within an inner periphery of the rigid, fuel dispensing spout.
The fuel dispensing passage and the vapor recovery passage of the vapor assist hose can be defined as coaxial passages within the vapor assist hose. The vapor recovery passage surrounds the fuel dispensing passage.
The fuel dispensing nozzle and spout assembly can further comprise a boot defining a proximal end and a distal end. The proximal end is coupled to the spout attachment end of the fuel dispensing nozzle. The distal end is configured for communication with a surface proximate a fuel tank inlet pipe of a vehicle during fueling. The boot can comprise a pliable material, which can be synthetic or polymeric, for example, polyester-type polyurethane rubber. The pliable material can be transparent and the boot can further comprise at least one convolution positioned between the proximal and the distal ends of the boot proximate the bend in the rigid, fuel dispensing spout. The convolution is configured to allow the boot to flex when in communication with the surface proximate the fuel tank inlet pipe of the vehicle during fueling.
The boot can further comprise an annular rib positioned on the distal end of the boot. The annular rib is configured to fit against the surface proximate the fuel tank inlet pipe of the vehicle during fueling. The boot is configured to maintain a sufficient level of vacuum within the fuel storage and dispensing system to ensure adequate vapor recovery and accurate system diagnostics. The boot is positioned surrounding the rigid, fuel dispensing spout and defines an annular passage configured for receiving fuel vapor displaced from the fuel tank inlet pipe of the vehicle during fueling. The annular passage is in communication with the vapor return opening in the spout attachment end of the fuel dispensing nozzle. The boot is configured to prevent fresh air from entering the vapor return opening in the spout attachment end of the fuel dispensing nozzle.
The fuel dispensing nozzle and spout assembly can further comprising at least one pressure relief chamber in communication with the fuel dispensing passage of the vapor assist hose. The pressure relief chamber can comprise at least one bleed hole and a fluid volume sufficient to enable fuel traveling within the fuel dispensing passage of the vapor assist hose to create a pressure relief vacuum within the chamber. The pressure relief vacuum has a magnitude sufficient to compensate for high temperature pressure build-up in the vapor assist hose. The pressure relief chamber can comprise a check valve that is configured so that during fueling, fuel that has collected within the pressure relief chamber is expelled from the pressure relief chamber.
In accordance with still another embodiment of the present invention, a pressure relief assembly is provided comprising at least one pressure relief chamber in communication with a fuel dispensing passage of a coaxial, vapor assist hose. The pressure relief chamber comprises at least one bleed hole and a fluid volume sufficient to enable fuel traveling within the fuel dispensing passage of the vapor assist hose to create a pressure relief vacuum within the chamber. The pressure relief vacuum has a magnitude sufficient to compensate for high temperature pressure build-up in the vapor assist hose. The pressure relief chamber can further comprise a check valve that is configured so that during fueling, fuel that has collected within the pressure relief chamber is expelled from the pressure relief chamber.
In accordance with yet another embodiment of the present invention, a vapor recovery boot assembly is provided comprising a boot positioned surrounding a rigid, fuel dispensing spout and defining a proximal end, a distal end, and a medial portion. The proximal end is configured for coupling with a fuel dispensing nozzle comprising a vapor return opening. The distal end defines a flange configured for communication during fueling with a surface proximate a fuel tank inlet pipe of a vehicle. The medial portion is positioned between the distal and proximal ends and defines an annular passage. The annular passage is configured for receiving fuel vapor displaced from the fuel tank inlet pipe of the vehicle during fueling. The annular passage is in communication with the vapor return opening in the fuel dispensing nozzle. The rigid, fuel dispensing spout further defines a non-coaxial fuel tube. The non-coaxial fuel tube can be configured to be substantially dripless.
The boot can comprise a pliable material, which can be transparent. The pliable material can be synthetic or polymeric, such as polyester-type polyurethane rubber. The medial portion of the boot can further comprise a least one convolution that is configured to allow the boot to flex when in communication during fueling with the surface proximate the fuel tank inlet pipe. The flange can further comprise an annular rib that is configured for communication during fueling with the surface proximate the fuel tank inlet pipe. The boot is configured to prevent fresh air from entering the vapor return opening in the fuel dispensing nozzle. The proximate end can further comprise a furrow, the fuel dispensing nozzle can further comprise a knurl, and the furrow is configured for attachment to the knurl with a removable hose clamp.
In accordance with still yet another embodiment of the present invention, a Venturi shut-off assembly for a fuel dispensing nozzle and spout is provided comprising a fuel dispensing nozzle defining a hose attachment end and a spout attachment end. A rigid, fuel dispensing spout coupled to the spout attachment end of the fuel dispensing nozzle defines a non-coaxial fuel tube. The non-coaxial fuel tube can be configured to be substantially dripless. The spout further defines a sidewall, a shutoff sensing tube positioned within the spout, and an inlet hole. The inlet hole completely traverses the sidewall of the spout and the shutoff sensing tube is in communication with the inlet hole. The shutoff sensing tube further defines a check valve and the shutoff sensing tube is coupled to a Venturi shut-off valve positioned within the fuel dispensing nozzle.
Accordingly, it is a feature of the present invention to provide a fuel storage and dispensing system which is effective in reducing fugitive emissions. It is also a feature of the present invention to provide a fuel dispensing nozzle and spout assembly, and a vapor recovery boot assembly, which is effective in reducing fugitive emissions. It is also a feature of the present invention to provide a pressure relief assembly and a Venturi shut-off assembly, which both further reduce the emission of harmful volatile organic compounds into the environment. These and other features and advantages of the invention will be more fully understood from the following detailed description taken together with the accompanying drawings. It is noted that the scope of the appended claims is defined by the recitations therein and not by the specific discussion of features and advantages set forth in the present description.